In a steering system of a vehicle, a steering shaft is coupled at one end with a steering wheel by a rim. The steering shaft is usually inserted into a steering column to pass therethrough to be rotatable and the steering column is fixed to a body of the vehicle so as to partially constitute a structural arrangement for supporting a steering shaft and a steering wheel in an interior cabin formed in the body of a vehicle. Such a steering shaft included in the structural arrangement for supporting a tilt steering device is rotatably supported at a lower end on the body. The steering column is supported at its middle portion to a body with a tilt lock since it is movable to different positions in an up-and-down direction so as to be tiltable, as disclosed in Japanese Utility Model specification published before examination under Publication Number 59-99867.
In such a structural arrangement, the lower end of the steering column is rotatably attached by a shaft through a lower bracket to a dash panel bracket The middle portion of the steering column is attached through an upper steering column bracket to an upper steering bracket by a shaft with a tilt lock.
During a collision of the vehicle, a driver's body is caused to lean forward. It is known that if the driver's body is caught by the steering wheel, the shock is absorbed by the deformation of the steering wheel. For example, when a driver's chest strikes against the steering wheel, a rim of the steering wheel may be deformed to absorb the shock.
When the driver's body is caught by the steering wheel on the occasion of a collision of the vehicle, it is preferable that the steering column is fixed to the vehicle body so that the steering column does not rotate.
However, in such a previously proposed structural arrangement for supporting a tilt steering column and a steering wheel in the interior cabin of a vehicle as described above, since the middle portion of the steering column is supported on the body by a tilt lock so as to be able to change, its up-and-down position and the lower end of the steering column is rotatably supported on the body on the occasion of a collision of the vehicle, only the lower end of the steering column is pushed backward and the steering column projects upwardly by rotating forwardly around the tilt lock installed at the middle portion of the steering column.